The invention relates to a suction installation for a multi-cylinder internal combustion engine with a container-like manifold device from which extend suction pipes that adjoin directly or indirectly a cylinder head.
A known suction installation, DE-OS No. 34 20 703, includes a container or vessel with a first hemispherically shaped housing, on which is mounted a second conically shaped housing. Individual suction pipes which are extended to the container, extend on the inside of the container adapted to be filled with a liquid medium and more particularly up to the second housing. Apparently, a sealing wall is provided between the two housings. This construction entails the disadvantage that the volume in the second housing is hardly sufficient so as to be able to make available in a functionally correct manner the pulsating air demand of an internal combustion engine, for example, with four cylinders. Additionally, the geometry of the circularly shaped throttle valve housing and of the second conical housing causes flow losses by reason of the velocity distribution of the air--slowly along the edge, rapidly in the center--which impair disadvantageously the power output behavior of the internal combustion engine.
It is the object of the present invention to provide an internal combustion engine-suction installation which, combined with a spatially favorable construction and reduced weight, contributes to the gas-dynamic optimization of the suction side of the internal combustion engine.
The underlying problems are solved according to the present invention in that the shape of the entire manifold-like device, especially its inner surface delimiting an interior space corresponds to a sphere and the suction pipes connected to the manifold-like device are aligned with their center lines to the center of the sphere, whereby the suction pipes supply the cylinders of the internal combustion engine with air from the interior space of the sphere.
The advantages principally achieved with the present invention reside in that the gas-dynamic friction losses are significantly reduced by the spherical shape of the manifold-like device whereby the efficiency--torque, consumption--of the internal combustion engine is improved. Additionally, the sphere-manifold-like device requires little space with a given volume which, on the one hand, simplifies the layout of the equally long suction pipes and, on the other, facilitates the accommodation of auxiliary aggregates of the internal combustion engine. Owing to the favorable ratio of surface to volume with this manifold-like device, the material expenditure for the suction installation is less with the consequence that the latter has less weight and can be manufactured more simply.
The alignment of the suction pipes toward the sphere center not only assures good gas flow conditions, but also that the connection of the suction pipes at the manifold device can be constructed circumferentially funnel-shaped as desired. As a result of the alternate supply of air by way of the suction pipes to the cylinders and more particularly in dependence on the ignition sequence of the internal combustion engine, it is achieved that the entire sphere volume is available to each suction pipe during the suction stroke, as a result of which a defined good mixture distribution is achieved. Stated differently, a mutual impairment of the suction pipes by unequal spacings, for example, as would be the case with a non-spherical geometric shape of a manifold-like device can be dispensed with.
Therebeyond, the suspended arrangement of the manifold-like device contributes to the fact that the space in the immediate vicinity of the internal combustion engine can be utilized well. Finally, the connection of the suction installation with the cylinder head and the support at the vehicle creates a decoupled bearing support which has a noise-reducing effect.